Electrical equipment in the computer and electrical component industries utilizes loose hardware, comprising internally and externally-threaded standoffs (known as "female screw locks"), in addition to spacer washers, lock washers, and nuts to attach data receptacles to the equipment chassis; and further, the data plug to the receptacle. FIG. 1 shows a typical assembly of parts found at the rear of the chassis for connecting incoming and outgoing data cables. These data cables may be comprised solely of electrical contacts, fiber optic terminals, air connectors, or any combination of the foregoing.
These data plugs and receptacles typically have a modified, elongated "D" shape to ensure proper orientation in their mounting holes and also proper orientation with the mounting plugs. Such connectors have become known as "D" connectors, and due to the relatively small size, more typically known as "D subminiature", or "D-sub" connectors. Shell sizes, pin configuration, and mounting holes have been standardized throughout the world and all manufacturers meet these standards. In addition, many manufacturers have their own proprietary plug/receptacle configurations developed to meet customer's special applications.
In almost all cases, however, the matter of loose hardware was never addressed, nor was the present volume of consumption of such connectors anticipated. Thus, the industry continues to attach connectors to chassis and plugs with conventional loose hardware, in spite of the high labor costs associated with manually assembling this hardware.
Currently, in the connector industry the number of contact circuit pair in a D-sub connector may range from 9 to 50 contacts, with a typical connect/disconnect force of 12-ounces per contact pair, thus, for the maximum number of contact pairs, this connect/disconnect force is approximately 600-ounces or 37 pounds. Technology is moving toward increasing this density to 100 contact pairs, and as the need for higher electrical current density increases, the connect/disconnect forces will also increase. Therefore, there is a need in the art for electrical cable connector fasteners which can provide a higher connect/disconnect force than is currently available. Meeting this need is difficult because with the standardized D-sub connector configuration, there are space limitations which prohibit simply increasing the dimensions of the fasteners. In a D-shaped electrical connector panel, there is very limited space between the edge of the D-shaped cutout in the panel, and the center line of the fastening screw.
Due to the adoption of manufacturing standards mentioned above, such assembly screws either have 4-40 Unified, or M3 metric threads. These small diameter screws may be used for both pulling in, or jacking out, the plug from the receptacle and are suitable only for connectors having a limited number of contacts. As the need for high density (more numerous) and greater power (larger) connectors are needed, these small diameter screws are not strong enough to engage or disengage such higher density connectors.